1. Field of the Invention
The invention relates generally to mold apparatus for making closure caps for bottles and the like, of the kind having at least one serrated portion and a threaded portion. More particularly, it relates to a unique mold core for use in forming a stepped closure cap by a deep drawing process.
2. Description of the Prior Art
Closure caps of the same general kind as that of the invention are known. They generally consist of a blank formed from an aluminum sheet, which has a thread rolled therein after the closure cap blank is put on the threaded neck opening of a bottle.
Apart from the fact that such a closure cap requires considerable material and the process for making and installing it is complicated, it must be noted that the thread on the neck of the bottle usually deviates from the ideal circular shape, so that an absolute seal of the closure is often not provided, especially for carbonated beverages. There is need for a cap closure which is directly produced in its final form, which seals effectively when installed, and which can be made of synthetic material or the like. The present invention is directed to satisfying that need.